It is known to produce patterns on a substrate by exposing the substrate to a source of directional deposition or etching through a pattern in a stencil. Typically (although not essentially) the substrate is arranged such that a normal to the substrate passes through the directional source. For the portion of the substrate close to this normal the pattern produced on the substrate is substantially the pattern of the stencil. As one moves away from this normal however the source appears to be inclined to the substrate. The thickness of the stencil results in stencil shadowing with the pattern on the substrate being slightly displaced from the corresponding portion of the pattern of the stencil This ‘pattern run out’ limits the accuracy with which patterns can be deposited or etched onto a substrate. This pattern run out is also referred to as pattern registration (overlay).
The method according to the present invention seeks to overcome this problem.